This proposal requests support for the purchase of an Acuson Sequoia C512 Echocardiography System, which will be used for echocardiographic analysis of cardiovascular structure and function in experimental animal models of common human cardiovascular diseases. The system will be housed and operated in the Echocardiography Laboratory, which is an integral part of the Mouse Cardiovascular Phenotyping Core Facility at the Center for Cardiovascular Research at Washington University. It will join an existing dedicated ultrasound system, which was purchased through the Shared Instrumentation Grant mechanism and has been in operation for over 6 years. Due, in large part, to the availability of the current cardiac ultrasound system, the Cardiovascular Phenotyping Core has evolved to a highly successful, large volume facility, performing over 1,400 echocardiographic studies annually. It has served researchers from a wide variety of disciplines across multiple departments and schools at Washington University in St. Louis, as well as nationwide. Indeed, the users' work depends on the availability of high quality echocardiographic analysis. As a result of the quality and success of the research projects of the Core users, there has been a steady rise in the volume and complexity of the echocardiographic studies over the years to the point that even with maximum utilization and productivity of the Core Laboratory, the current system can no longer adequately satisfy the demands and scientific needs of the User Group on a timely and efficient basis. The Acuson Sequoia C512 is a highly versatile ultrasound system capable of performing cardiovascular imaging in animal subjects with widely different heart sizes ranging from dogs to mice. Its state-of-the-art technical features are uniquely suited for cardiovascular phenotyping in genetically manipulated mice. Installation of the new ultrasound system will provide immediate benefit to the Core users in accomplishing the scientific goals of their NIH funded projects.